public class example3_1 {
  public static void main (String args[]) {
    char a1='十',a2='点',a3='进',a4='攻';
    char secret = 'A';
    a1 = (char)(a1^secret);
    a2= (char)(a2^secret);
    a3= (char)(a3^secret);
    a4= (char)(a4^secret);
   System.out.println("密文:"+a1+a2+a3+a4);
   a1 = (char)(a1^secret);
    a2= (char)(a2^secret);
    a3= (char)(a3^secret);
    a4= (char)(a4^secret);
   System.out.println("密文:"+a1+a2+a3+a4);
  }
}
